Due to the finite supply of fossil energy sources, the global environmental damage caused by fossil fuels, increasing energy demand, and economic forces, society is becoming compelled to diversify energy resources. One such technology that has received significant attention is the use of solar energy.
Solar energy collection systems are used for a variety of purposes, for example, as utility interactive power systems, power supplies for remote or unmanned sites, and cellular phone switch-site power supplies. An array of energy conversion modules, such as, photovoltaic (PV) modules, in a solar energy collection system can have a capacity from a few kilowatts to a hundred kilowatts or more, depending upon the number of PV modules, also known as solar panels, used to form the array. The solar panels can be installed wherever there is exposure to the sun for significant portions of the day.
In general terms, a solar energy collection system includes an array of solar panels arranged in the form of rows and mounted on a support structure. The solar panels are oriented to optimize the solar panel energy output to suit the particular solar energy collection system design requirements. Solar panels may be mounted on a fixed structure, with a fixed orientation and fixed tilt, or may be mounted on a tracking structure that aims the solar panels toward the sun as the sun moves across the sky during the day and as the sun path moves in the sky during the year. Tracking the sun can lead to a significant increase in annual radiation falling on the tracked surface, thus an increase in efficiency, relative to a fixed structure.
Significant technological progress has been achieved in the design and production of solar panels, accompanied by increased efficiency and reductions in manufacturing cost. Another a major cost element involved in the establishment of a wide-scale solar energy collection system is the cost of the support structure used to mount the solar panels of the array in proper position for receiving and converting solar energy.
Many different support structures for solar panels have been proposed and implemented. Unfortunately, many of these support structures are so costly and mechanically complicated that they have hindered the widespread introduction of solar arrays for the generation of commercial and industrial electricity. In addition to the mechanical complexity of such support structures, costs are also largely influenced by the number and size of the footings to which the support structure is fastened. The cost of footings is governed by labor costs, soil conditions, and site preparation costs, as well as the cost and availability of concrete.
A shortage of cement, the basic ingredient for concrete, has been exacerbated by a continued housing boom and import constraints, and has resulted in significant increases in the cost of cement. The shortage of cement afflicts many regions, and is particularly problematic in the United States across the sunbelt, from Florida to California. Of course, the sunbelt is likely to also be the desired location for large solar energy collection systems due to the abundant sunshine.
As a result of the cost and mechanical complexity of existing solar energy collection systems, and the costs associated with constructing the footings to which the support structure is fastened, there has been an unwillingness to proceed with wide-scale solar energy collection systems, despite their obvious advantages in terms of desired environmental effects and conservation of fossil energy sources.